This invention relates to data setting systems for terminal units in remote supervisory and controlling system and, more particularly, to a system for setting data for the terminal units in the system for remotely supervising and controlling loads on the terminal units connected respectively through a two-wire line to a central control unit for time-divisional, multiplex transmission of supervisory, controlling and the like data.
The remote supervisory and controlling system of the kind referred to is effectively employed in lighting control system, fire and security system or the like which is installed within constructs.
1. Disclosure of Prior Art
In the supervisory and controlling system of the kind referred to, the terminal units are provided respectively with an adjustable setting element so that various data can be stored in a memory section within the terminal unit normally through manual operation of the element or the data thus stored can be modified. When, on the other hand, the installed location of the terminal unit is such a place as a room ceiling, an extremely narrow space or the like where the unit is not easily accessible for a system operator, the data storing or modifying operation has been made extremely complicated.
In U.S. Pat. No. 4,535,333 to Joseph W. Twardowski, there has been suggested a controlling apparatus employing a so-called transceiver system for use in a remotely controlled opening and closing garage door and the like, in which the data setting or modification is carried out between a transmitter and a receiver included in the system so that the garage door opening and closing in any desired manner can be realized. Further, another system has been suggested in U.S. Pat. No. 4,807,052 to Toshio Amano, in which an object to be remotely controlled, for example, is provided with a nonvolatile memory so as to be operable as controlled in accordance with stored data in the memory, the control data being written in the nonvolatile memory or being modified in response to an optical wireless transmission from a writing means.
However, while either one of the foregoing U.S. patents allows the control data or the like in the receiver or the controlled object to be written and transcribed, i.e., modified from a remote position, the Twardowski patent still has not been at a level adaptable to the optical wireless transmission and reception, and the Amano patent has been still far from suggesting the time-divisional, multiplex transmission of the supervisory, controlling and the like data or, in particular, any address setting system though the optical wireless transmission and reception system has been thereby suggested. Accordingly, it has been demanded to provide a data setting system for the terminal units in the remote supervisory and controlling system employing the multiplex data transmission, the setting system allowing the address data and the like data settable by means of the optical wireless transmission and reception, so as to improve the remote supervision and control.
2. Technical Field
A primary object of the present invention is, therefore, to provide a system which can readily set from a remote position the data in the terminal units provided respectively with a nonvolatile memory by means of the optical wireless transmission and reception in the remote supervisory and controlling system employing the multiplex transmission.
According to the present invention, this object can be realized by a data setting system for terminal units in a remote supervisory and controlling system in which a plurality of the terminal units having each a set address are connected through a two-wire line to a central control unit, and a time-divisional and multiplex data transmission is carried out between the central control unit and the terminal units with a transmission signal transmitted from either the central control unit or the terminal units, wherein each of the terminal units is provided with a memory for holding various function data and a light receiver for receiving an optical wireless signal including said data to be written in the memory, the optical wireless signal being prepared in an operating means provided separately from the terminal units for transmission to them, and the function of the respective terminal units is changed over in response to the function data in the memory.
Other objects and advantages of the present invention shall become clear from following description of the present invention detailed with reference to embodiments shown in accompanying drawings.